Scaffolding



United States Patent SCAFFOLDING Robert Warren Hyre, Chattanooga, Tenn.

Application January 29, 1957, Serial No. 636,988

5 Claims. (Cl. 304-40) This invention relates to improvements in scafiolding, and more particularly to an improved scaffold brace attaching and locking means serving to attach and lock the cross braces to the end and/or intermediate frames of sectional scaffolding, the present application being a continuation-in-part of my prior application Serial No. 485,753, filed February 2, 1955, now Patent Number 2,830,855.

A main object of the invention is the provision of a scaffold-brace attaching and locking means for sectional scaffolding which is characterized by simple and relative ly inexpensive construction, which is featured by its ability of greatly increasing the speed of erection and dismantling of scaffolding as compared to the prior brace-end connecting and securing means, which is easy to operate and which further possesses superior locking properties as compared to the prior cross-brace connections.

Another more particular object of the invention is the provision of a brace-lock for scaffolding which requires the minimum of manual manipulation in attaching and locking the cross braces to the end frames of sectional scaffolding.

A further object of the invention is the provision of a novel and highly effective gravity-wedge type of crossbrace attaching and locking means for sectional scafiolding which insures maximum locking effect.

Yet another object of the invention is the provision of an effective lock for the cross braces employed in sectional scaffolding characterized by a gravity-wedge type of locking member which is pivotally hung from a shouldered stud projecting from a frame part to which the brace end is adapted to be connected, wherein said locking member and shouldered stud are so related and arranged that following initial assembly of the brace end to the shouldered stud the wedge member automatically exercises a preliminary locking effect thereon, which may be supplemented by a later manipulation of the gravity wedge designed to achieve full locking effect.

A still further object of the invention is the provision of a cross brace attaching and locking means for sectional scaffolding characterized by a bodily invertible gravity wedge adapted in its normal position to exercise a' preliminary locking effect, and in its inverted position to exercise a greatly increased locking effect on the crossbrace end associated therewith.

Yet another object of the invention is the provision of a cross-brace attaching and locking means as aforesaid wherein a cam lock serving to secure the inverted gravitywedge in its full locking position is also provided.

The above and other objects and advantages of a cross brace attaching and locking means for use in sectional scaffolding according to the invention will appear from the following detailed description thereof, in which reference is had to the accompanying drawings illustrating a preferred physical form thereof, in which:

Fig. 1 is a perspective view illustrating a typical and locking means of the invention;

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Fig. 2 is a perspective view illustrating a connection about to be effected between the end of a cross brace and a shouldered stud carried by a frame part as herein contemplated;

Figs. 3-6, inclusive, are detail views illustrating the various operations of attaching and locking the cross brace to a frame part by the attaching and securing means of the present invention;

Fig. 7 is an enlarged view illustrating the parts in their fully locked position; and

Fig. 8 is a detail view illustrating the action of the cam lock in locking the gravity wedge in its full locking position.

Referring to the drawings, Fig. 1 typifies a well known form of sectional scaffolding made up of end frames 10, 11 which are held erected by a plurality of pairs of cross braces 12, 13 extending between and attached to the vertical members of the end frames, said scaffolding illustratively supporting a platform 16. Both the end frames 10, 11 and the cross braces 12, 13 may be and preferably are of standard construction and hence said parts form no part of the present invention except as they may enter the claimed combination or combinations directed to the means for attaching and locking the ends of said cross braces to the vertical members of the end frames, to which the present invention is directed.

It is also to be observed that since the cross'braces 12, 13 serve the very important function of maintaining the end frames 10, 11 and hence the scaffolding as a whole in set-up or erected condition, the means for attaching and locking said cross braces to the end frames must of necessity be such as to provide the utmost in security to the final scaffolding. At the same time, it is highly desirable that the attaching and locking means employed be capable of being made and broken quickly, and with a minimum of effort, so as to both simplify and speed up the erection and dismantling of the scaffolding. Finally, when the great number of attaching and locking means required for even a small scaflold installation is considered, it will be appreciated that the means employed to attach and lock the cross-brace ends should, if possible, be of inexpensive construction consistent with the high degree of locking action required.

The aforesaid numerous and also to an appreciable degree conflicting requirements of a means for attaching and locking cross braces to the end and/ or intermediate frames of sectional scaffolding are ably satisfied by the attaching and locking means of the present invention now to be described. As seen more particularly in Fig. 2, each such means, in common with the brace-end attaching and locking means of my aforesaid application Serial- No. 485,753, employs a projecting shouldered stud generally designated 20 and a specially constructed attaching end generally designated 30 formed on or provided at each end of the cross braces. However, as distinguished from the wing-nut type of locking means characterizing the brace lock of my aforesaid application, the present improved brace lock employs as its locking means a socalled gravity wedge designated 40.

Describing said parts in greater detail, the aforesaid shouldered stud 20 is affixed at its head end 21 as by .welding to a usually vertical part of the scaffolding end frame such as a side member or post 10a thereof and extends horizontally from said post, as best seen in Figs. 3-7. The stud is further provided with a largerdiameter shoulder section 22 adjacent its head end and terminates at its other or shank end in a smallerdiameter shank portion 23. Preferably, the shoulder 24 between the aforesaid largerand smaller-diameter sections of the stud is beveled so as to facilitate axial movement of the cross-brace end onto the larger diamete r shoulder section 22, as will be described.

As also seen in Fig. 2, the aforesaid cross-brace attaching end 30, as is formed or provided at each end of all cross braces, comprises a flat, generally hook-like element which may be fashioned from strap or bar stock and is secured as by welding to one flange of its brace i2 or 13, which latter preferably has conventional L-section, although it of course may have other suitable angular section or it may be formed tubular. As explained in my prior application Serial No. 485,573, the aforesaid hook member is formed with a part-circular hole 31 which opens through a side edge thereof via a slot 32 extending straightway between said hole and its side edge. The walls or edges which define said slot include narrowed neck portions 33a, 331; which together define a small-width throat adjacent the hole end of the slot and outwardly inclined or divergent portions 34a, 34b which define the mouth or entrance end of the slot. As is well understood, the divergent edge portions 34a, 34b serve to facilitate preliminary hooking of said attaching end 30 with a shouldered stud 20, and the provision thereof is a feature of advantage when said parts are not in good alignment.

According to a further feature of the invention, while the diameter of the part-circular hole 31 is slightly larger than that of the shoulder section 22 of the stud 20, the width of the narrow throat portion of the slot is less than the diameter of said shoulder section, being intermediate said diameter and that of the shank end 23 of the stud. Hence, it is possible to couple the attaching end 30 with the shouldered stud 20 only by first hooking said attaching end onto the smaller-diameter shank end 23 of the stud and then pushing it axially along the stud until it moves over the shoulder section 22 thereof. It follows that the attaching end 30, when engaged or hooked over the shoulder section 22, can be uncoupled therefrom only by backing it axially off same until its hole 31 encircles the smaller-diameter shank end 23 of the stud. Axial movement of the attaching end in either direction is facilitated by beveling the edges of the hole 31, as indicated at 35.

Next considering the novel gravity-wedge form of locking means according to the present invention, the aforesaid gravity wedge 40 illustratively comprises an elongated U-member whose side arms 42a, 42b are spaced a distance enabling them to comfortably straddle the largerdiameter shoulder section 22 of the stud 20. Preferably, the wedge is connected to the stud for both pivotal and sliding movement by means of a rotary cross pin 4-4 having bearing in and extending transversely through said shank end 23, the cross pin having projecting ends which are received in corresponding elongated slots 46a, 46b cut or otherwise formed in the aforesaid wedge side arms 42a, 42b. As seen in Figs. 3-7, inclusive, the opposite side edges 47a, 47b and 48a, 48b of the wedge arms are relatively inclined, and the slots 46a, 46b are disposed parallel to the aforesaid side edges 47a, 48a and thereby are inclined to the opposite edges 48a, 48b. Also to be observed is that the slots 46a, 46b extend substantially the length of the wedge and more particularly they terminate short of the corresponding narrow-end edges of the wedge arms a distance which is appreciably less than the spacing of the slots from the side edges 47a, 47b. With the construction so far described, it will be appreciated that the wedge 40 has a normal position shown in Fig. 3 in which it hangs by gravity from the cross pin 44, with its narrow end disposed upwardly and its corresponding side edges 47a, 47b disposed toward the frame part 1011, but that it may be manually inverted and permitted to lower by gravity to a diametrically opposed position as shown in Figs. 6 and 7.

By reference to Fig. '8, it will be understood that the cross pin ends which extendthrough slots 46a, 46b of the wedge member 40 are so shaped that they function as p eccentrics dreams capable of engaging with substantial pressure on the inner edges of said slots responsively to the cross pin being turned throughout a limited arc of approximately as may. be effected by an integral handle 50 projecting forwardly from one end of said cross pin. Analysis of Fig. 8 will show that when the cross pin 44 is turned 90 from its normal position in which its eccentric end portions are vertically disposed in the wedge slots 46a, 46b, said eccentric ends bear with substantial friction against the relatively inner edges of the slots and in so doing serve to tightly secure the wedge in its full clamping position aforesaid.

According to a further feature of the present invention, the corresponding corners 52 between the narrow-end edges of the wedge side arms 42a, 42b, and the aforesaid side edges 47a, 47b of said arms have identical arcuate configuration giving them the shape of a cam nose. Finally, the cross pin 44 is axially located along the length of the shank end 23 of the stud 20 at a point which is spaced from the stud shoulder such as, when the wedge is in its normal position aforesaid, to space the aforesaid corresponding corners 52 from said shoulder a distance which is less than the thickness of a cross-brace attaching end 30. This spacing of cross pin from shoulder is also such, taking into account the relative spacing of the slots 46a, 46a from the side edges 48a, 48b of the wedge arms, as, when the wedge is in its inverted and at least partially lowered position, to space said side edges 48a, 48b from the frame part 10a a distance which is similarly less than the thickness of said cross-brace attaching end 30.

The manner of operation of the above described cross brace attaching and locking means will now be briefly explained. Normally, the gravity wedge 40 hangs from the cross pin 44 positioned as shown in Fig. 3, that is, with its corresponding edges 47a, 47b disposed toward from the head end of the stud 20. In this position of the wedge, its corner portion 52 is adapted to be engaged by the under edge of a cross-brace attaching end 30 upon said attaching end being positively moved in lowering direction against said corner. As shown in Fig. 4, positive engagement of said attaching end against the corner 52 of the wedge swings the latter throughout an upward arc of approximately 90", as permits the attach ing end to be lowered onto and to hookably engage with the shank end 23. Then, as seen in Fig. 5, return movement of the Wedge 40 to its normal position causes or at least assists said attaching end 30 to move axially over the larger-diameter shoulder section 22 of the stud and thereupon prevents said attaching end from backing oil said shoulder section. Thus, with the parts assembled as in Fig. 5, they are preliminarily locked together, although not finally so, and it is to be observed that this preliminary locking operation can be performed by a workman standing several feet away from the stud 2t) and gravity wedge 40, and further that with practice it can be efiected with a simple and quick or snap action.

To obtain full locking action, the wedge 40 is swung approximately from its Fig. 5 to its Fig. 6 position and released, whereupon it lowers by gravity. In so do ing, the locking wedge shifts bodily toward the head end of the stud, during which movement its aforesaid clamping edges 48a, 48b clamp the attaching end 36 of the brace against the stud head 21. Finally, if it is desired to positively secure the wedge in its full locking position as aforesaid, the cam-lock handle 50 is swung approxi mately 90 in counterclockwise direction, whereby the eccentric end portions of the cross pin 44 which extend through the slots of the wedge are caused to press with substantial friction against the side edges thereof then adjacent the head end of the stud, such friction se curing the wedge in its locking position aforesaid.

To-uncouple the cross-brace attaching end 30 from the stud 20, the cam lock is released by turning the handle 50 approximately 90 in clockwise direction. Thereupon, the still inverted wedge is raised the full length of the slots 46a, 46b and is permitted to swing 90 to a horizontal position, as provides the requisite spacing between said attaching end to be backed off the shoulder section 22 and finally unhooked from the shank end of said stud. When such has been effected, the wedge is released, whereupon it swings by gravity to its normal position as shown in Fig. 3.

Without further analysis it will be appreciated that a means for attaching and locking the ends of cross braces to the end or intermediate frames of sectional scaffolding as described in the foregoing achieves the objectives of the invention as explained in the foregoing. However, as many changes may be made in carrying out the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. Means for attaching and locking a scaffold cross brace to the end and/or intermediate frames of sectional scaffolding comprising, in combination, a shouldered attaching stud atfixed to and projecting at a right angle from a frame part and having a larger-diameter shoulder section disposed adjacent the frame part and a smaller-diameter shank end which is separated from the shoulder section by a shoulder, an attaching end on the cross brace having a part-circular hole of diameter substantially equaling that of said shoulder section and which opens through a side edge of said attaching end via a slot having effective width intermediate the diameters of the shoulder section and the shank end of the stud, a gravity wedge having relatively inclined side edges and a pin-and-slot connection to the shank end of the stud, the slot being parallel to one side edge of the wedge and thereby inclined to the other edge thereof and extending well into the narrow end of the wedge and terminating short of the narrow end edge a distance substantially less than the spacingof the slot from said one side edge, the corner between said narrow-end edge and said one side edge of the wedge having arcuate configuration giving said corner the shape of a cam nose, the pin being axially located along the length of the shank end of the stud at a point which is spaced from the stud shoulder a distance such as, when the wedge is in its normal position in which it hangs by gravity from the pin with its narrower end upwardly disposed and its said one side edge disposed toward the frame part, to space said corner from said shoulder a distance which is less than the thickness of the attaching end, and which is also such as, when the wedge is in the inverted and at least partially lowered position in which its other side edge is disposed toward the frame part, to space said other side edge from the frame part a distance which is also less than the thickness of said attaching end, the construction and arrangement being such that, when the wedge in its normal position as aforesaid, said attaching end may be pre liminarily secured to the stud by movement of said attaching end transversely of the stud and against said wedge corner, as effects said attaching end camming said wedge to a partially raised position in which said attaching end can be hooked over its shank end followed by re-lowering of the wedge by gravity as in turn efiects said corner camming said attaching end axially on to the shoulder section of the stud, and being further such that the attaching end may be finally secured to the stud following its aforesaid preliminary securement by manually swinging the wedge to its inverted position and permitting it to lower to a position in which it clamps said attaching end against the frame part.

2. Scaffolding cross-brace attaching and locking means substantially as set forth in claim 1, wherein the pin mounts means for frictionally locking the wedge in its inverted and partially lowered position aforesaid.

3. Scaffolding cross-brace attaching and locking means substantially as set forth in claim 1, wherein the pin is rotatable in the shank end of the stud and mounts eccentric means disposed within said slot for frictionally locking the wedge in its inverted and partially lowered position aforesaid.

4. Scaffolding cross-brace attaching and locking means substantially as set forth in claim 1, wherein said wedge comprises an elongated U-member, and said pin and slot connection comprises a cross pin extending through the shank end of the stud and having projecting ends which are received in aligned slots in the side arms of the U-member, each slot corresponding to the aforesaid wedge slot.

5. Scaffolding cross-brace attaching and locking means substantially as set forth in claim 1, wherein said wedge comprises an elongated U-member and said pin and slot connection comprises a cross pin extending through the shank end of the stud and having projecting ends which are received in aligned slots in the side arms of the U-member, each slot corresponding to the aforesaid wedge slot, said pin ends being eccentric in direction as to engage and frictionally lock against corresponding edges of the slots responsively to the cross pin being turned throughout a limited angle, and a handle extension on the cross pin for turning the same thereby to frictionally lock the wedge in lowered position.

References Cited in the file of this patent UNITED STATES PATENTS Great Britain Dec. 7, 1955 

